Chronic granulomatous disease (CGD), an inherited disorder of phagocytic leukocyte function, is characterized by recurrent infections with catalase-positive organisms. Gastrointestinal (GI) tract involvement, present in the majority of affected individuals, may be present initially and recurrently, mimics other entities such as inflammatory bowel disease, and causes substantive morbidity and mortality. Disorders of motility, ulceration, obstruction, and infection (e.g., abscesses) occur from the mouth to the anus and stereotypically manifest with vomiting, diarrhea, abdominal pain, weight loss, and fever. Careful physical examination, in concert with appropriate diagnostic studies, is necessary to delineate intraabdominal pathologic processes. Abdominal radiographs, ultrasonography, computerized tomography, and endoscopy are useful ancillary diagnostic procedures. Drainage of accessible abscesses, antimicrobial therapy based on organisms cultured from blood and tissue, and interferon gamma may lead to suppression or eradication of infections and resolution of symptoms. Corticosteroids are useful for gastric outlet obstruction and sulfasalazine and cyclosporine for large bowel disease. Gallbladder dysfunction may be ameliorated, as in our patient, with administration of cholestyramine.